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    <title>Tahoe-LAFS - Reliability Tool</title>
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<h1>Tahoe-LAFS Reliability Tool</h1>

<p>Given certain assumptions, this page calculates probability of share loss
over time, to help make informed decisions about how much redundancy and
repair bandwidth to configure on a Tahoe-LAFS grid.</p>

<div n:render="forms" />

<h2>Simulation Results</h2>

<p>At the end of the report span (elapsed time <span n:render="report_span"
/>), the simulated file had the following properties:</p>

<ul>
    <li>Probability of loss (no maintenance):
        <span n:render="P_loss_unmaintained"/></li>
    <li>Probability of loss (with maintenance):
        <span n:render="P_loss_maintained"/></li>
    <li>Average repair frequency:
        once every <span n:render="P_repair_rate"/> secs</li>
    <li>Average shares generated per repair:
        <span n:render="P_repair_shares"/></li>
</ul>

<p>This table shows how the following properties change over time:</p>
<ul>
  <li>P_repair: the chance that a repair was performed in the most recent
  check period.</li>
  <li>P_dead (unmaintained): the chance that the file will be unrecoverable
  without periodic check+repair</li>
  <li>P_dead (maintained): the chance that the file will be unrecoverable even
  with periodic check+repair</li>
</ul>

<div>
<table n:render="sequence" n:data="simulation_table">
  <tr n:pattern="header">
    <td>t</td>
    <td>P_repair</td>
    <td>P_dead (unmaintained)</td>
    <td>P_dead (maintained)</td>
  </tr>
  <tr n:pattern="item" n:render="simulation_row">
    <td><n:slot name="t"/></td>
    <td><n:slot name="P_repair"/></td>
    <td><n:slot name="P_dead_unmaintained"/></td>
    <td><n:slot name="P_dead_maintained"/></td>
  </tr>
  <tr n:pattern="empty"><td>no simulation data!</td></tr>
</table>
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